The Bethune Flight 124 airmiss in 1951:

"While flying in the left seat on a true course of 230 degrees at a position of 49-50 North and 50-03 West, I observed a glow of light below the horizon about 1,000 to 1,500 feet above the water. We both observed its course and motion for about 4 or 5 minutes before calling it to the attention of the other crew members... Suddenly its angle of attack changed, its altitude and size increased as though its speed was in excess of 1,000 miles per hour. It closed in so fast that the first feeling was we would collide in midair. At this time its angle changed and the color changed. It then [appeared] definitely circular and reddish orange on its perimeter. It reversed its course and tripled its speed until it was last seen disappearing over the horizon. Because of our altitude and misleading distance over water it is almost impossible to estimate its size, distance, and speed. A rough estimate would be at least 300 feet in diameter, over 1,000 miles per hour in speed, and approached to within 5 miles of the aircraft."

Picture of a Navy R5D transport. The R5D is a variant of the C-54 transport, whose civilian version is known as the Skymaster.

Sketches by witnesses:

This is an annotated sketch by Graham Bethune of what he saw through the cockpit of the C-54.

This is an annotated drawing by Graham Bethune explaning the movements and changes of aspect of the flying disk during the whole observation.

This is an annotated drawing by the pilot who disconnected the autopilot as he arrived in the cockpit and saw the object on a collision course with the C-54. He watched it fly with the C-54 during one or two minutes and then disappear over the horizon.

An artist made this drawing, according to the witnesses accounts, to show the course of the giant disc towards the aircraft and away from it, as it would have been seen from a side viewer.